Nail puller



C. N. BUCK NAIL PULLER Oct. 9, 1951 2 sheetsTsheet 1 Filed Feb. 27, 1948oct. 9,1951 c, N, BUCK 2,570,914

' NAIL FULLER Filed Feb. 27, 1949 sheets-sheet 2 @9.7 .@5151 JQ-Q9 A.aarencejlfuC/.

Patented Oct. 9, 1951 YUNITED STATES ijiiit @FFICE 11 Claims. 1

The present invention relates to nail pullers and Certain improvedconstructions and arrangements of elements by which a nail is quicklywithdrawn rectilinearly from its lodgment.

Nail pullers heretofore used have been of the hammer-lever constructionin which a vert1cal shaft is pivoted to a horizontal shoe, and both theshoe and shaft are provided with jaw members to grip the nail when theshaft is tilted in the direction of the shoe. upon the shaft is used asa slide hammer to drive Athejaws into the wood on opposite sides of thenail before the jaws are levered to grip the nail. Thereafter the shaftis levered about the shoe to -pull the nail through an arc which bendsthe nail and renders it unt for further use.

Such nail pullers require long shafts so that the back stroke of thehammer will not displace the jaws fromvtheir proper position. On theother hand, a heavy hammer and a short stroke is eX- tremely tiring toan operator when a nail puller is to be used vfor any length of time.Not only this, but the conventional nail pullers require' a great dealof space around the nail to allow for leverage movement of the shaft andthe direction of this leverage is limited because the shoe has to restupon a substantial length of the board 'in' which the nail is driven,for obvious reasons. Furthermore, the slightest deviation from the planeof leverage movement causes the shoe to slip and break away from thenail with corresponding danger of injury to the operator exert ingleverage pressure upon the nail puller.

The invention eliminates these diiiiculties and 'further'removes thenails without injury to them so that they can be reused again and again.The invention is further characterized by preserving the verticalspacing of the operators hands for easy management of operations withoutthe hands being endangered by relative moving parts as is the case withconventional nail pullers.

Another object of the invention is to provide a `nail puller whichretains its grip upon the nail Aly clear of the wood and resettingitself for pulling the next nail. 4

A further object of the invention is to grip ,th

nail only when the jaws are deep enough in the wood to close upon theshaft of the nail below the head and then to close the jaws with a com-A heavy slip sleeve bination of cooperating forces which not only guidesthe jaws to a closed position but locks the jaws closed with a reactionforce which preferably provides a lost motion between the nail pullerbody and the board holding the nail so that initial reverse movement ofthe parts gains the advantage of an inertial head start to jerk andvunseat the nail from its set position to start its withdrawal. With thehead start thus provided, the full weight of the nail puller body isbrought into play in preference to the use of only part thereof or theuse of additional weight.

Furthermore, the invention exerts a tugging action without hammering andeliminates objectional noise generally accompanying conventional nailpulling.

Other and further objects of the invention, including simplicity ofconstruction and operation, will .become apparent from the drawings, thedescription relating thereto, and the appended claims. f

Referring now to the drawings,

Fig. 1 is a front view, partly in section,v of a construction embodyinga preferred form of the invention in position ready to pull a nail;

Fig. 2 is a sectional view of the construction shown in Fig. 1, as takenupon line 2-2 Fig. 3 is a bottom view of the lower end of theconstruction shown in Fig. 1;

Fig. 4 is a section taken upon line i--li in Fig. 1;

Fig. 5 is a section taken upon line 5 5 in Fig. l

Fig. 6 is a diagrammatical View taken from the front of the constructionshown in Fig. 1 with the jaws open and the nail pulling head in raisedposition;

Fig. '7 is similar to Fig. 6 showing thejaws as they contact the woodaround a nail head;

Fig. 8 shows another position of the nail pulling head in which the jawshave penetrated the wood and closed upon the nail; and

Fig'. 9 shows another position of the head with-the nail withdrawn andabout to be ejected.

The invention contemplates driving two pivoted jaws into a board onopposite sides of a lnail head and, as the jaws move in, contracting andlocking the jaws in contracted position below the nail head; lifting thejaws a full distance ,to remove and clear the nail from the board, and'thereafter 'expanding the jaws to discharge the -nail withoutmutilation. It is preferred that the jaws be so mounted on a guidewaymember that they overrun the guideway when driven into the board, thuslifting the guideway member clear of the board during the time that thejaws are being contracted around the nail. This readies the nail pullerto exert the extra heavy force needed to start the nail by providing amoment during which the relative movable parts of the puller acquire arelative momentum before effort is exerted upon the nail. Under thisrelative momentum the guideway member again engages the board with a,blow and reaction effort sulcient to dislodge the nail from its setposition prior to fully withdrawing the nail.

The apparatus employed embodying the invention includes a fluid actuatedpiston I disposed in a cylinder II and a piston rod I2 connected theretowhich slides in and out through a front head I3 on the cylinder. Aspacer I4 upon the piston rod determines the outward limit of movement.A second or rear head I5 is provided at the upper end of the cylinderand the two heads are tied together by stud bolts I6 and nutsv I1disposed at opposite ends thereof. Two

vof the nuts upon one side and at the front end of the cylinder secure alaterally projecting handle 2i] in place, while two nuts upon theopposite side and at the back end of the cylinder secure a second handle2I in place so that the device can be manipulated by holding the handle23 in the left hand and the handle 2| in the right hand.

The piston is moved by fluid pressure such as air under a commonly usedpressure of ninety pounds per square inch. The air is received throughthe nipple 22 threaded in the rear head I5 and directed into the chamber23 of a valve 24 which has a slide element 26 and plate urged to onelimit of its movement by a spirng 25. The slide element at the endopposite the spring 25 has a push rod 21 extending axially therefrom.The rod passes through gland packing 28 and into engagement with theshort arm 30 of a lever SI pivoted to the rear handle 2| as at 32. Adepressing of the lever 3I drives the element 26 against the spring andmoves it to its secondary position. Releasing the handle permits thespring to return the element 26 to its starting position.

A slide valve member 26a is engaged and driven by the element 26. Thismember is disposed so as to slide over pairs of ports I9 and I9a. In thestarting position shown, the pair of ports I9 is in communication,connecting the upper end of the cylinder to the atmosphere. One of theports I9a of the second pair is open to the space 23 to admit air to thelower end of the cylinder, and the vent port of the pair is closed. Whenthe handle 3I is pressed, the slide valve member 26a is moved to theother side, connecting the pair of ports I9a to vent the lower part ofthe cylinder and connecting one of the ports I9 to the space 23 tosupply air to the upper part of the cylinder.

In its starting or resting position the air under 'pressure is directedto ilow into the cylinder on the rod side of the piston through thevalve port I9 and a conduit 33 running down the outside of the cylinder.This returns and holds the piston at its rearward position. The rearportion of the cylinder is vented to atmosphere to permit this. In thesecondary position of the valve, as when the lever is depressed, thefront end of the cylinder is vented to atmosphere and the air underpressure is directed into the cylinder behind the piston to force itfrontwardly.

Thus, depressing the lever drives the piston rod downwardly with aquick, power-driven action,

and releasing the lever will cause a quick, powerdriven lifting orretraction of the piston rod.

This control of the piston can be accomplished by the right hand whilethe cylinder is held in supported working position.

A sleeve guiding the piston rod I2 is held in place upon the forwardhead I3 by machine screws 36 and has attached to it as shown in Fig. 2 abar 31 which has a, longitudinal groove 38 on the piston rod side of thebar. The end face of the bar is knurled as at 40 and the two adjacentcorners on the piston side of the bar are faced 01T as at 4I to leave apointer contour 42. The pointer is used to locate the bar `with respectto a nail 43 and the knurled end face 4B prevents slipping. At the upperend of the groove 38 an interchangeable stop member 44 is held againstlongitudinal displacement by the head of a machine screw 45 restingsnugly in a hole `4'6 in the bar.

The exposed end of the piston rod I2 is threaded as at 41 to engage in athreaded boss 5I upon a housing member 50 where it is held againstloosening by a setscrew 52. The housing member slides up and down on thebar, against the front face 53 thereof, and is guided by a cover member54 channeled as at 55 to receive the bar as held in place by machinescrews 56 whose heads are preferably countersunk in the housing wherethe stock is thick enough to receive them without weakness.

The housing member and cover member define a cavity 51 within which thenail gripping and release elements are supported. Referring to Fig. 6,two jaw elements are pivoted to each other as at the pivot pin 58located intermediate their ends so that the expansion of the arms 6I!causes the jaws 6I to close towards each other.

The jaws are curved inwardly like the ends of a crescent and preferablyare made out of tool steel to withstand striking against hard wood,metal binding tape or sheet steel. The arms are shaped to define a spacebetween them and tapered upwardly at 62 to provide camming surfacesbetween them. A block or cam 64 is slidably mounted in the groove 38upon the bar 31 where it lies between the arms 6U inside the cammingsurfaces 62, the upper corners 65 engaging the camming surfaces beingrounded for easy sliding along the camming surfaces. As shown in Fig. 2,the block has a well 66 in it receiving a spring pressed ball 61engageable in a detent 68.

A tension spring 1U, with upset loops at each end secured against theouter faces of the arms by screws 1I, urges the jaws BI to their openposition by drawing the arms towards each other.

At the upper or rearward limit of the housing movement, the floatingblock engages the stop 44 and is held or driven thereby from between theends of the arms 60. At the lower or forward limit of the housingmovement, the oating block engages the lower end of the groove and isheld there as the housing approaches its limit of movement as determinedby the length of the sleeve I4. During the last increment of downwardmovement under the force of the piston, the block is stationary butmoves along the camming surfaces 62 as the housing carries the armsdownwardly and moves between the .arms to accomplish their separationand the corresponding closure of the jaws. In this position the ballengages in the detent to keep the block from jarring out of position on`the back stroke until such time as the stop 44 engages the block andcarries it from between the ends of the arms as already mentioned. I

The driving force between the housing and the jaws is carried mainly attwo points so that the load is not only distributed between severalelements, but the jaws are steadied against veering. This isaccomplished by two pins 14, one upon each arm, slidable laterally intransverse grooves in the housing as the arms are expanded. Lateralexpansion is allowed iorby mounting the head 'l2 of the pivot pin toslide in a vertical groove 'i3 in the housing. The two pins 74 carrymost of the load of protraction and retraction insofar as the workeffort upon the jaws is con-- cerned. However, these pins sharethe loadand in conjunction with the pivot pin support the jaws against veeringwhen driven downwardly to grasp the nail below the head.

In operation, the resting position of the head is shown in Fig. 6 whereit is held in its re-y tracted position by air pressure admitted to thecylinder on the rod side of the piston as when the valve 26 is in itsresting position under the influence of the compression spring 25. Thepointer 42 is located opposite the head 39 of the nail 43 where it isembedded in a wooden board 29. This is best accomplished by holding thehandle in the left hand and the handle 2i in the right hand.

The lever 3| is then depressed. This moves the valve to its alternateposition, air be1ow the piston is vented to the atmosphere, and airunder pressure enters the cylinder above the piston. This drives thepiston downwardly, carrying with it the head and the floating block 64.

The next station of interest is reached when the block 54 reaches theend of the groove 353 in its downward movement as shown in Fig. 7. Atthis time the jaws have begun to pierce the wood and the rounded uppercorners G5 of the block 64 engage the cam surfaces 62 of the arms 6B. Inthis position the lower end of the bar 3i is still in contact with thewood and the head is still moving downwardly.

The downward drive of the head has ended in Fig. 8. The jaws have beendriven deeper into the wood. The arms 6B have been driven along therounded corners and havebeen expanded by the block to close the jawsaround the nail head. The spring pressed ball 61 has engaged in thedetent 68, and the overthrow provided .between the bar 31 and the head50 as determined by the length of the sleeve I4 has operated to raisethe lower end 4U of the bar away from the board as a preferredpreliminary to the back or reverse stroke of the piston.

The lever 3| is then released. The valve resumes its normal position.The v.upper portion of the cylinder is vented to the atmosphere and airunder pressure is fed into the cylinder below the piston. When thisoccurs the head and bar begin to move with respect to each other withquick acceleration. They bar being raised above the board a shortdistance enables the building up of this relative inertial movementbetween the bar and head before a withdrawing force is exerted againstthe nail. This movement in substance builds up sufficient energy thatwhen the bar again engages the board with a blow-like force, thereaction jars the nail loose from its embedded position and the pistonthereafter merely tugs amoving nail. Invariably the nail is loosened andwithdrawn with one application of force but if it is not, manipulationof the lever will cause repeated blows and reaction of elements untilthe -nail is dislodged enough that the direct pull of the piston isadequate to complete withdrawal of the nail.

The next station of interest is then shownin Fig. 9'where the nail hasjust cleared the board and is about to be ejected. The nail is straightand as good as new for reuse. As shown, the block has just come intocontact with the stop 44 and can go no further. But the head having apredetermined distance yet to go disengages the detent 68 and moves thearms from off the sides of the block whereupon the block is freed andthe arms are also freed to be contracted by the compression spring 10with sufficient snap and force the fracture they impose upon the wood.v.The :shoulder is useful in preventing vthe-jaws from going too deep ifa soft spot in the woodis encountered. This preserves the overthrow orlost motion lift of the bar from the Wood so that inertial starting blowis assured each time.

Consequently, although a preferred embodi- 'rnentis shown, it will beapparent to those skilled `in the art from the description of preferredforms how various and further modifications can be vmade withoutdeparting from the spirit of the invention, the scope of which iscommensurate with the appended claims.

What is claimed is:

1. In a nail puller, the combination of a guide member, a slide member,a loose element having cam surfaces thereon carried by one member formovement with respect to the other member, a pair of stops for limitingmovement of the loose element with respect to the other member, nailgripping jaws pivotally mounted on the slide member including 'actuatingarms cooperating with-said cam surfaces, said element being disposedbetween said arms and movable when one stop is approached to close saidjaws by displace- ,Y ment of said arms and to release the jaws when theother stop is reached by movement from be- -tween the arms, said slidemember having a greater distance of travel than said element.

2. Ina nail puller, a support member for engaging a workpiece, a pair ofjaws reciprocably mounted with respect to said member for gripping anail in the workpiece, and means for driving the jaws beyond the supportmember into the workpiece around the nail to lift the support from ncontact with the workpiece, said means also driving the support intocontact with the workpiece vinary to and as a part of applyingwithdrawing Y movement of the jaws upon the nail.

in close proximity to the nail to deform a portion of the workpiecesurrounding the nail prelim- 3. In a nail pull-er, a support member forengaging a workpiece in close proximity to the nail 'portion f theworkpiece proximate to the nail and develop an inertial blow to move aportion of the workpiece with respect to the nail to overcome startingfriction and apply withdrawing movement Aof the nail grasping memberupon th nail.

4. In a nail puller, the combination including a guide member, a slidemember, a loose element carried by the slide member, a pair of stops onsaid guide member for limiting motion of said loose element in bothdirections; a pair of jaws pivotally mounted on said slide member andincluding actuating arms, said element bearing against said arms whenone stop is approached to close the jaws by displacement of the arms andmoving away from said arms when the other stop is reached to permit thejaws to open, and resilient means for opening said jaws under suchconditions.

5. In a nail puller, a support member for engaging a workpiece, meansfor reciprocably mounting a pair of jaws for gripping a nail in theworkpiece, said means being so constructed and arranged as to permitsaid jaws to move to a position extending beyond the end of the supportmember into the workpiece around the nail to lift the support fromcontact with the workpiece a distance substantially in excess of thenormal penetration of the jaws in the workpiece, means for driving thejaws to said position from a retracted starting position, said lastmentioned means also driving the support into contact with the workpieceto develop an inertial movement preliminary to applying withdrawingmovement of the jaws upon the nail.

, 6. In a nail puller, a support member for engaging a workpiece, a headincluding a pair of jaws reciprocably mounted on said member, said jawsbeing adapted to penetrate said work piece, the clearances between saidmember and said head being such as to permit said pair of jaws to vbemoved to a position beyond the end of the -support member a distancesubstantially greater than the penetration of the workpiece by the jawsto lift the support a substantial distance from contact with theworkpiece, and means for driv.. ing the jaws to such position, said lastmentioned means also driving the support into contact with the workpieceto develop an inertial movement preliminary to applying withdrawingmovement of the jaws upon the nail.

7. In a nail puller, a piston memberand a cylinder member includingmeans for reciprocating the piston under power in both directions, asupport element for engaging a workpiece carried by one of the members,a pair of jaws for gripping a nail in the workpiece carried by the othermember, said jaws being adapted to penetrate said work piece, theclearances of said members being such as to permit said jaws to extendto a position beyond the support member a distance substantially greaterthan the penetration of the workpiece by the jaws at one limit ofrelative movement between the jaws and the support, and means foropening and closing said jaws at opposite limits of said relativemovement.

8. In a nail puller, the combination of a guide member, a slide membermounted for reciprocable movement with respect to said guide member,jaws carried by said slide member to grip a nail to be pulled, a loosecam element for actuating said jaws, said element being loosely carriedby said slide member for longitudinal movement with respect to the othermember, and stops on one of said members for limiting movement of saidcam element, said element closing said jaws when one stop is reached andreleasing said jaws when the other stop is reached and said slide memberhaving a greater distance of tuating said jaws, and stops for limitingmovement of said movable element with respect to said guide member, saidmeans for actuating said jaws closing said jaws when said movableelement reaches one of said stops and opening said jaws when it reachesthe other stop and said slide member having a greater distance of travelthan the movable element.

10. A nail puller comprising a guide member, a slide member, a looseelement having a cam surface' thereon carried by the slide member formovement relative to the guide member, a jaw pivotally mounted on theslide member and having an actuating arm, a pair of stops for limitingmovement of said element, said element being movably mounted adjacentsaid arm and movable when one stop is approached to close said jaw bydisplacement of said arm as the cam surface cooperates with said arm andto release said jaw when the other stop is reached by movement relativeto said arm, said slide member having a greater distance of travel thansaid element, and means for reciprocating said slide member.

11. The method of `withdrawing a nail embedded in a workpiece includingmoving a nail engaging element toward said workpiece at a relativelyhigh velocity to cause said element to penetrate said piece beneath thehead of said nail, moving the element into contact with said nail toengage same, and striking a blow against the workpiece in closeproximity to said nail head while simultaneously exerting an 'upwardforce upon said element to withdraw said nail.

CLARENCE N. BUCK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 779,028 Condon Jan. 3, 19051,516,155 Santarelli Nov. 18, 1924 1,771,712 Jimerson July 29, 1930

